'Striatus': First 3D-Printed and Unreinforced Concrete Bridge

Researchers at ETH Zurich  have used 3D printing to build load-​bearing concrete structures that require significantly less material and no steel reinforcement or mortar. ETH architects and engineers in collaboration with partners from industry showed how this works with a footbridge in Venice. Using an additive process, the “Striatus” bridge was built with concrete blocks that form an arch much like traditional masonry bridges. This compression-only structure allows the forces to travel to the footings, which are tied together on the ground. The dry-assembled construction is stable due to its geometry only. The researchers developed the 3D-printed concrete with the company Incremental3D. The concrete is applied at specific angles such that they are orthogonal to the flow of compressive forces.